Makefile: fix DESTDIR

Signed-off-by: Igor Gnatenko <i.gnatenko.brain@gmail.com>

diff --git a/Makefile b/Makefile
index b2b64e7..36e75c5 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -38,11 +38,11 @@ LIBVER_MINOR=`sed -n '/define LZ4_VERSION_MINOR/s/.*[[:blank:]]\([0-9][0-9]*\).*
 LIBVER_PATCH=`sed -n '/define LZ4_VERSION_RELEASE/s/.*[[:blank:]]\([0-9][0-9]*\).*/\1/p' < lz4.h`
 LIBVER=$(LIBVER_MAJOR).$(LIBVER_MINOR).$(LIBVER_PATCH)
 
-DESTDIR=
-PREFIX = /usr
-CC    := $(CC)
-CFLAGS?= -O3
-CFLAGS+= -I. -std=c99 -Wall -Wextra -Wundef -Wshadow -Wstrict-prototypes -DLZ4_VERSION=\"$(RELEASE)\"
+DESTDIR?=
+PREFIX ?= /usr
+CC     := $(CC)
+CFLAGS ?= -O3
+CFLAGS += -I. -std=c99 -Wall -Wextra -Wundef -Wshadow -Wstrict-prototypes -DLZ4_VERSION=\"$(RELEASE)\"
 
 LIBDIR?= $(PREFIX)/lib
 INCLUDEDIR=$(PREFIX)/include